Electric vehicle charging device and method for controlling same

Abstract

The present invention relates to an electric vehicle charging device and to a method for controlling same. The electric vehicle charging device includes a plurality of charging cables installed in one electric vehicle charger. After battery charging of a vehicle, which has arrived first, is completed using one charging cable, a next vehicle is immediately charged using another charging cable such that even in a state where the vehicle, which has arrived first, does not leave a charging station, the next vehicle can be charged. Accordingly, it is possible to improve convenience of an electric vehicle user, and minimize waiting time for charging. Therefore, it is possible to improve the operational efficiency of the electric vehicle charger.

The invention claimed is: 
     
         1 . An electric vehicle charging device comprising:
 an AC-DC converter configured to convert AC power supplied from a power supply unit into DC power;   a plurality of DC switches connected in parallel to an output terminal of the AC-DC converter to supply or cut off the DC power;   a plurality of AC switches connected in parallel to the power supply unit to supply or cut off the AC power;   a plurality of connectors respectively connected to one DC switch of the plurality of DC switches and one AC switch of the plurality of AC switches;   a plurality of charging cables extending from the DC switch or the AC switch to the connector, to be respectively connected between the switch and the connector; and   a controller configured to control the plurality of DC switches and the plurality of AC switches to selectively or simultaneously charge batteries of a plurality of electric vehicles connected to the plurality of connectors,   wherein the controller is configured to
 start DC rapid charging for a first charging vehicle connected to one connector of the plurality of connectors, 
 supply a remaining AC current of the power supply unit to a second charging vehicle connected to an other connector of the plurality of connectors to perform AC slow charging of a battery of the second charging vehicle, wherein the remaining AC current is remained as a battery SOC of the first charging vehicle being rapidly charged increases, DC rapid charging power for the first charging vehicle is reduced, and a margin for charging power available on a power line is created, and 
 switch the DC rapid charging for the first charging vehicle to AC slow charging to charge a battery of a next vehicle waiting for charging with DC rapid charging when the DC rapid charging power for the first charging vehicle is less than maximum AC slow charging power for the first charging vehicle. 
   
     
     
         2 . The electric vehicle charging device of  claim 1 , wherein each of the plurality of connectors is configured to support both rapid charging and slow charging. 
     
     
         3 . The electric vehicle charging device of  claim 1 , wherein the connector is implemented as a combo  1  or combo  2  capable of using both DC and AC at a same time. 
     
     
         4 . The electric vehicle charging device of  claim 2 , wherein charging ports of the plurality of electric vehicles are respectively connected to the plurality of connectors, and
 wherein the controller is configured to control the plurality of DC switches and the plurality of AC switches to constantly maintain charging power charged to the plurality of electric vehicles at a preset value.   
     
     
         5 . The electric vehicle charging device of  claim 1 , further comprising:
 a display panel having a charging start button for charging a battery of an electric vehicle,   wherein the controller is configured to charge the batteries of the plurality of electric vehicles in an order of pressing the charging start button based on charging request times, and charge a battery of a next electric vehicle in order when the charging of a battery of an electric vehicle being charged first from among the plurality of electric vehicles is completed.   
     
     
         6 . The electric vehicle charging device of  claim 1 , wherein the battery SOC of the first charging vehicle being rapidly charged further increases to further reduce the DC rapid charging power, and
 wherein the controller is configured to supply a further remaining AC current of the power supply unit to a third charging vehicle connected to an other connector of the plurality of connectors to perform AC slow charging of a battery of the third charging vehicle, wherein the further remaining AC current is remained after using the remaining AC current for the second charging vehicle to the maximum.   
     
     
         7 . The electric vehicle charging device of  claim 1 , wherein the controller is configured to charge the batteries of the plurality of electric vehicles based on charging completion times, start charging from a vehicle with an earlier charging completion time, and determine charging priorities according to an order connected to the connector when the charging completion times of the plurality of electric vehicles overlap. 
     
     
         8 . The electric vehicle charging device of  claim 1 , further comprising:
 a charger case that accommodates the AC-DC converter, the plurality of DC switches, the plurality of AC switches, and the controller therein,   wherein the plurality of charging cables and the plurality of connectors are provided on an outer side of the charger case.   
     
     
         9 . A method of controlling an electric vehicle charging device having an AC-DC converter configured to convert AC power supplied from a power supply unit into DC power, the method comprising:
 controlling a plurality of DC switches connected in parallel to an output terminal of the AC-DC converter to supply or cut off the DC power;   controlling a plurality of AC switches connected in parallel to the power supply unit to supply or cut off the AC power;   connecting a plurality of connectors respectively connected to the plurality of DC switches and the plurality of AC switches through a plurality of charging cables to charging ports of a plurality of electric vehicles, respectively;   selectively or simultaneously charging batteries of a plurality of electric vehicles connected to the plurality of connectors;   starting DC rapid charging for a first charging vehicle connected to one connector of the plurality of connectors;   supplying a remaining AC current of the power supply unit to a second charging vehicle connected to an other connector of the plurality of connectors to perform AC slow charging of a battery of the second charging vehicle, wherein the remaining AC current is remained as a battery SOC of the first charging vehicle being rapidly charged increases, DC rapid charging power for the first charging vehicle is reduced, and a margin for charging power available on a power line is created; and   switching the DC rapid charging for the first charging vehicle to AC slow charging to charge a battery of a next vehicle waiting for charging with DC rapid charging when the DC rapid charging power for the first charging vehicle is less than maximum AC slow charging power for the first charging vehicle.   
     
     
         10 . The method of  claim 9 , wherein each of the plurality of connectors is implemented as combo  1  or combo  2  that supports both rapid charging and slow charging. 
     
     
         11 . The method of  claim 9 , wherein the charging of batteries of a plurality of electric vehicles controls the plurality of DC switches and the plurality of AC switches to constantly maintain charging power charged to the plurality of electric vehicles at a preset value. 
     
     
         12 . The method of  claim 9 , further comprising:
 a display panel having a charging start button for charging a battery of an electric vehicle,   wherein the charging of batteries of a plurality of electric vehicles charges the batteries of the plurality of electric vehicles in an order of pressing the charging start button based on charging request times, and charges a battery of a next electric vehicle in order when the charging of the battery of the electric vehicle being charged first from among the plurality of electric vehicles is completed.   
     
     
         13 . The method of  claim 9 , wherein the charging of the batteries of the plurality of electric vehicles comprises:
 further increasing the battery SOC of the first charging vehicle during the DC rapid charging for the first charging vehicle to further reduce the DC rapid charging power for the first charging vehicle that charges a battery of the first charging vehicle; and   supplying a further remaining AC current of the power supply unit to a third charging vehicle connected to an other connector of the plurality of connectors to perform AC slow charging of a battery of the third charging vehicle, wherein the further remaining AC current is remained after using the remaining AC current for the second charging vehicle to the maximum.   
     
     
         14 . The method of  claim 9 , wherein the charging of batteries of a plurality of electric vehicles comprises:
 charging the batteries of the plurality of electric vehicles based on charging completion times, and   wherein the charging based on the charging completion time comprises:
 starting charging from a vehicle with an earlier charging completion time, and 
 determining charging priorities according to an order connected to the connector when the charging completion times of the plurality of electric vehicles overlap.